Mount for fixed length automobile antenna



Jan. 24, 1950 M. R. FRIED'BERG MOUNT FOR FIXED LENGTH AUTOMOBILE ANTENNA Filed April 19, 1947 EL. Z

, INVENTOR E61 M/LTo/v R. FRIED/BERG BY m, MMM

ATTORNEYS Patented Jan. 24:,y 1950 MOUNT FOR FIXED LENGTH AUTOMOBILE ANTENNA Milton R. Friedberg, Cleveland Heights, Ohio, as-

signor to The Gabriel Company, Cleveland, Ohio, a corporation of Ohio Application April 19, 1947, Serial No. 742,635

(Cl. Z50-33) 4 Claims. l

yThis invention relates to an improvement in meansy for mounting automobile antennas, and, particularly, for lixed length antennas mounted on the roof of automobiles or motor vehicles.

The conventional antenna for automobile radio sets is a ltelescopic antenna mounted on the cowl or some other portion of the automobile below the roof of the automobile which is usually of the sedan or coupe type. While such antennas are quite satisfactory for long-wave commencialbroadcast reception, they are far from satisfactory for short-wave reception or transmission, as for police, taxicab, or two-Way telephone use. In the latter type of reception or transmission, maximum performance is obtained with a vertical antenna having a definite, xed length with respect to an effective ground plane. Such optimum conditions are not obtainable with conventional antenna mounts located on the cowl of an automobile or even, as has been done sometimes, located on the roof immediately above the windshield. In such cases, any portion of the body of the car which extends above the base of the antenna may tend to shield it and thus effectively vary the length of the an tenna, depending upon the position of the car with respect to the direction from which the signal is coming. Furthermore, in such case there can be no effective groundV plane extending in all directions for at least an antenna length'irom the base of the antenna, Y

These diiliculties have been overcome with the antenna mount vherein disclosed, which positions an antenna rod extending preferably vertically from the highest point of the roof of an automobile (e. g., of a sedan or coupe type having a steel roof). Thus` no matter from which direcn tion a signal is received, the antenna is not shielded by any portion of the car. Furthermore, with the antenna so mounted, for each model of each make of car, a constant effective ground plane is located andv the proper fixed length of antenna for a given wavelength can be determined.

Because an antenna rod mounted` as above described extends above the roof of thek car, it is liable to be bent or broken in use and must be readily replaceable in the mounting in such a manner that positive electrical and mechanical connection is assured. The mount therefor must 2 be weatherproof, both with respect to the means for mounting and disrnounting the antenna rod and for sealing thel opening in the car roof. A

In view of the foregoing, it is an object of the present invention to provide a new and improved mounting for an antenna rod which mayV be positioned on the roof of an automobile, is attractive in appearance, provides a seal preventing the leakage of moisture into the interior of the vehicle, providesA a ground connection for the outer conductor of a lead-in cable, iirmly and rigidly supports the antenna rod, and yet enables the rod to be readily removed or replaced without disassembly of the mounting.

A. further object of the invention is the provision of a new and improved antenna mounting including an antenna supporting member having an aperture for receiving the base of an antenna and readily accessible and operable means movable into and out of the aperture for detachably engaging the base, and, while permitting a ready exchange of antennas, prevents accidental loss or removal of an installed antenna.

A still further object of the invention is the provision of a new and improved automotive vehicle antenna rod mountinghaving a combina tion one-piece member having in one end an aperture for receivingV the base of an antenna and at the other end a lead-through bolt comu vmunieating to the interior of thevvehicle for connection with a lead-in cable.

Still another object of the invention is the provision of a new and improved antenna mounting for automotive vehicles or the like including an insulating plate and a grounding plate adapted to be positionedon opposite sides of a metal Wall comprising the vehicle body, the grounding plate having means for electrically engaging the metal lwall and grounding same, while both plates have sealing means on the side adjacent the metal wall for preventing the passage of moisture or other undesirable substances therebe tween.

The invention resides in certain constructions and `combinations and arrangements of parts, and Yfurther objects and advantages will be apparent to those skilled in the art to which it relates from the following description of the pref' 'ferred' embodiment described with reference t 3 the accompanying drawings forming a part of this specication, and in which:

Fig. 1 is an elevation, partly in section, showing an antenna mounting embodying the present invention installed on an automobile roof; and

Fig. 2 is a plan view taken along the line 2--2 of Fig. 1.

In the drawings, the highest point of a car roof I is drilled to provide an opening ll and three equally spaced bolt holes l2 are drilled radially about it. The antenna mounting is comprised of a base plate 2B of Bakelite or a similar rigid nonconductor having a radius greater than the radius of the bolt holes l2. The base plate 2Q is drilled in the center to provide an opening 2| which receives a chuck bolt 30 comprised of a threaded bolt portion 3 l, a collar 34, and a' larger socketed chuck 33. The collar 3i fits snugly in the opening 2l and carries a thin rubber washer 32 which nts between and spaces the base of the chuck and the top or exterior of the base plate 2t. The bolt portion 3| carries a nut 35 and a washer 3S which engages the underside of the plate 2B. Thus, by tightening the nut 35, the chuck bolt is secured to the plate and the opening 2i is sealed by the washer 32.

rThe chuck 33 is so called because it is drilled axially to provide an antenna socket 3'! and is tapped radially to receive pointed setscrews 38. The chuck 'bolt and setscrews are preferably of stainless steel or other non-corroding or nonrusting metal.

Between the base plate 26 and the car top i0 is a large annular rubber washer 2E having openings Corresponding to the openings i2 in the car roof Iii through which mounting bolts 23 extend from the exterior of the base plate 20 to the interior of the car roof. The bolts 23 also extend through a rubber washer 24 Similar to the washer 22 and a large steel grounding washer 25, both positioned on the interior of the car top. A lock nut 3S on each bolt 23 when tightened down sccurely positions the base plate 23 on the car top io, the opposite sides of Vthe car roof I6 being engaged by the sealing washers 22 and 24. The

grounding washer 25 is tapped to receive pointed setscrews 2l which extend through suitable openings in the rubber washer 24 to bite through any paint or rust which might be on the underside oi the car top it into the metal thereof, thus grounding the washer '25. The setscrews 2l may be locked in position after assembly by suitable means such as jam nuts 23.

-A iead-in cable dil, which is comprised of thc vconventional Vbraided ground shield about an in sulated-coaxial radio-frequency conductor is provided with a clip 4l soldered to the conductor and a grounding `wire 42 `soldered to the grounding shield. The clip 4l is fastened to the bolt portion ,3l or" the chuck bolt 39 by means of lock washer and nut 33 and the grounding wire 4l. is fastened to one of the setscrews 2 by means of a nut 44.

With the base plate 20 mounted as above described, the .mounting is ready to receive an antenna 58, which is simply a length ci small rod or heavy wire closely Vfitting the socket 31 and cut to the length determined by the wave length to be received and the effective ground Vplane provided by the roof of the particular model and make of car on which the antenna is mounted. The antenna 50 is quickly mounted by inserting it into the socket 31 and tightening the pointed setscrews 38 which bite into the antenna 50 and insure good electrical and mechanical connection regardless of weathering conditions or mechanical vibrations. The depth of the socket 31 may be as desired, either greater or less than that shown. With the depth shown, a slight adjustment of the effective electrical length of the antenna 50 may be made by controlling the depth of insertion of the base of the antenna into the socket, the setscrews 38 holding the antenna in any adjusted position.

Thus it will be seen that an embodiment of the invention has been described which accomplishes the objects of the invention hereinbefore enumerated and others, as well as providing a mounting which requires but a iew seconds to disinount a broken or bent antenna and replace it with a new one, and the mounting is generally impervious to exposure to grit in traic spray, sleet, vrain,'or other or like adverse weather conditions. Also, special formation of the end of the antenna, such as threading or other special ttings, is unnecessary.

Although in accordance with the provisions of the patent statutes this invention is described as embodied in concrete form and the principle thereof has been described together with the best mode in which it is now contemplated applying that principle, it will be understood that the apparatus shown and described is merely illustrative and that the invention is not limited thereto, since alterations and modifications will readily suggest themselves to persons skilled in the art without departing from the true spirit of this invention or from the scope of the annexed claims.

Having thus described my invention, I claim:

l.. A mounting for a radio antenna comprising a base adapted to be positioned on theouter side of an exterior panel of `a motor vehicle body and over an. opening in said panel and provided with an lopening adapted to register with said panel opening, means for rigidly securing said base to said panel and carried by the base and adapted to extend through said panel; and antenna supporting means having an enlarged socket portion aligned with said base opening and extending radially beyond the circumference thereof to overlie the base, a collar portion interfitting said base opening. and a bolt portion extending through said base opening and adapted to extend through said panel opening; adjustable means on said bolt portion for engaging said base to clamp the latter between said socket portion and said adjustable means and secure the supporting means lin position on said base, and means on said bolt portion and cooperating with said adjustable means to connect a lead-in to L* said antenna supporting means, said socket portion being provided'with an axially extending antenna receiving socket in longitudinal extension of and coaxially with said bolt portion and means for locking an antenna in said socket in coaxial extension of said bolt portion.

2. A mounting for a radio antenna as defined in claim 1 and wherein said socket portion, said collar portion and said bolt portion of said an# tenna supporting means are integral with each other.

3. A mounting for a radio antenna as defined in claim 1 and wherein the means for locking an antenna in the said socket of said socket portion includes setscrew means carried by said socket portion and extending radially of said socket and operable from the exterior of said socket portion.

4. A mounting for a radio antenna as defined in claim 1 and wherein said base is an insulating base adaptedto ,be positioned on the outer side .of an exterior metal panel of a motor vehicle body and wherein the means carried by said base for securing the latter to the panel also mounts insulating washers adapted to be located on opposite Sides of and in engagement with said panel, and a grounding plate provided with an adjustable grounding member adapted to have electrical Contact with said panel and provided with means for connecting a grounding wire to said grounding member.

MILTON R. FRIEDBERG.

REFERENCES CITED The following references are of record in the le of this patent:

Number UNITED STATES PATENTS Name Date Wharton July 6, 1937 Hruska Nov. 9, 1937 Wilckens June 11, 194D Ludwig Aug. 5, 1941 Ludwig Jan. 13, 1942 Snyder Mar, 14, 1944 Bryers July 9, 1946 Einneburgh June 29, 1948 

